【Objective】To analyze the advantages of transparent cap assisted endoscopy in the diagnosis and treatment of duode? nal diseases.【Methods】From September 2014 to December 2015，62 cases with suspicious duodenal diseases in the endoscopy cen? ter of our hospital randomly divided into transparent cap group（n = 31）and routine group（n = 31）according to the time sequence. The visual field resolution，success rate of image capture and operating time were compared in 2 groups.【Results】Thirty cases in transparent cap group had clear visual field definition，which was obviously higher than 9 cases in conventional group（96.8% vs 29%，P < 0.001）. Twenty-three cases in transparent cap group and 8 cases in routine group were successfully captured（90.3% vs 25.8%，P < 0.001）. The average operating time of the transparent cap group was significantly shorter than that of the conventional group（150+58 vs 95+36 seconds，P = 0.004）.【Conclusion】Transparent cap endoscope examination is more effective in the treat? ment of duodenal diseases，and the image capture is higher and the operation time is shorter.